Valve



Sept. 3, 1935- E. J. VENSQN 2,013,073

:VALVE Original Filedl March 27, 1930 2 Sheets-Sheet l EPN/e, 57. KS2/@mon Sept. 3, 1935.

E. J. SVENSON VALVE original Fiied March 27, 195o 2 Sheets-Sheet 2 Eu/@non ZIP/ze szfz/erzsom fg, ,LW/M @i Patented Sept. 3, 1935 UNlTEu STATES VALVE Ernest l. Svenson, Rockford, Ill. I

original application March 27, 1930, serial No. 439,306. Divided and this application April 10,

1930, Serial No. 443,037

24 Claims. (Cl. 121-45) My invention relates generally to fluid controlling devices, and more particularly to valve mechanism for use in hydraulic actuator systems. i

This application is a division of my co-pending application, Serial No. 439,306, filed March 27, 1930, wherein I have shown the present invention in operative association with an automatic material working apparatus or lathe.

I am aware that valve mechanisms have been used in connection with hydraulic actuator circuits, but my present invention presents a distinctimprovevment over prior valve mechanisms with which I am familiar. It is common practice in hydraulically controlling the actuation of machine tools' and the like to employ a high pressure fluid circuit for imparting a-feeding movement to the 'tool carriage, and to employ a low pressure circuit to lobtain increased fluid displacement and to charge a plunger pump in the high pressure circuit. The valves which have been Y used in connection'with such circuits have, as

a matter of necessity, been of an elongated cylindrical type provided with a multiplicity of ports. Such a construction has been necessary because these valves are directly connected with and serve to control both `the high pressure and low pressure fluids. In other words, these valves must be subjected to relatively long strokes. Because of this elongate construction considerabledifliculty has been experienced in obtaining a proper t throughout the extent of thevalve casing or sleeve, and this has caused excessive fluid leakage or slippage to take place. This will be more readily appreciated when it is understood that valves of the above mentioned type are usually interposed between the source of high pressure fluid supply and the actuator, and, in addition, are directly coupled with a low pressure source of fluid supply. In shifting from one extreme position to another, these valves must be carried past at least 4two feeding positions, as well as the neutral position, and as the valve is moved past these positions, there is always a tendency for pulsative and other undesirable effects to be occasioned within the actuator system. I have found it desirable to employ a hydraulic actuator system as disclosed in my aforementioned co-pending application, which precludes the necessity of employing these conventional elongate complicated -valve mechanisms and enables the use of a simple valve arrangement, and my present invention relates to this particular valve construction.

T"Ihus, mypresent invention contemplates the provision of a .valve mechanism of simple, durable,

and economical construction which may be employed in a hydraulic actuator system without subjecting said system to any of the aforementioned and other difliculties that have been experienced heretofore.

It is a further object of my invention to provide a valve mechanism of the type including a Valve member longitudinallyshiftable within a casing, which is so constructed as to eliminate the possibility of leakage or slippage and which may be shifted from one position to another with a minimum amount of effort. f

More specifically, it is an object of my present invention to provide a valve of the aforementioned shiftable type which need only be shifted through a relatively short distance, and hence lends itself to accurate machining and grinding operations during the manufacture thereof.

Still another object of my invention is to provide a simple and efficiently operable valve mechanism, which is particularly adaptable to control the reversal of fluid in low` pressure fluid circuits, which circuits are supplied with fluid from a continuously operable propelling mechanism or pump.

In addition to the aforementioned andother advantageous structural characteristics, my invention contemplates a valve mechanism which is equipped with efliciently operable means Ifor causing the instantaneous automatic reversal of the valve in response to the engagement therewith by a shiftable means such as one of the movable machine parts or dogs, and said valve mechanism is so arranged as to enable the same to be manually as well as automaticallycontrolled.

These and numerous other objects and advantages will be more apparent from the following detailed description when considered in connection with the accompanying drawings, wherein-4 Figure 1 is a plan View, shown partly in section, of a Vvalve mechanism which is representative of one embodiment of my invention, said mechanism being shown in operative ass ciation with a fragmentary portion of a machi e slide;

Figure 2 is a central longitudinal vertical sectional vieW of the valve mechanism taken substantially along the line 2-2 of Figure 1;

Figure 3 is a transverse vertical sectional view thereof taken substantially along the line 3-3 of Figure 1;

Figure 4 is also a transverse vertical sectional view taken along theline 4-t of Figure 1;

Figure 5 is still another transverse sectional view taken substantially along the line 5--5 of Figure 1, a` portion of the balancing member 55 Figure 9 is a fragmentary view disclosing the. t

manner in which a tool supporting carriage may be coupled with the dog supporting slide so as to effect the actuation of the valve in response f to the actuation of said carriage.

7' Referring now to the drawings more in'detail lwherein like numerals have been employedb to`- designate similar parts throughout the various figures, it will be seen thatOone embodiment of the invention comprises a valve mechanism which includes a central valve casing or sleeve I0. This casing or sleeve I6 is provided with a central bore for receiving and slidably supporting a rvalve member which is designated generally bythe numeral I2; Secured to ne end of the casing I0 is an end casing I4,l an secured to 'the oppol site end of the casing I0 is anend casing I6.

The central casing I0 `is provided with a base I8, Figures 4 and 5, which enables,l the entire mechanism to be conveniently mounted in any y suitable position as, for example, upon a machine frame 26 which is shown Iragm'entarily in thev various iigures. e l

A pipe line' 22 connects with one side of the casing I0. Figures 1 and 4, and communicates at its extremity with a pair of branch passages 24 and 26, Figure 1. Thispipe line 22 is adapted to be connected with any suitable source of uid supply as, for example, ay continuously 'operable gear pump 23, Figure 8. When thevalvemember I 2 occupies its neutral position, which I have shown in Figures 1 to 5 inclusive and particularly in Figure 1, uid which is introduced through the pipe line 22, `passes through' the branch passages` 24 and 25. Fluid from the branch passage 26 'passes through an annular valve port or passage 26, which at this interval communicates with one end of a longitudinalv passageway 30. The opposite extremity of this passageway 30 communicates with a chamber 32 provided within the end casing I6. Fluid from the branch passage 24 passes through an annularvalve port or passage 34, which port or passage also communicates with the chamber 32. This chamber 32 is adapted to communicate with a reservoir 35, Figure 8, through a pipe line 36, Figure 2. Thus, it will be apparent' that when` the valve member I2 occupies its neutral position, uid delivered thereto from an externalsource of'supply or gear pump 23 will jcirculate through the valve ports into the end chamberv 32, and ltihenge back to the reservoir 35 through the pipe -It is also to be noted that when the valve member I2 occupies its neutral position, Figure 1, said valve will be subjected tol equal fluid pressures at both extremities. The right end oi!v thevyalve member I2 is formed with a piston section 38 which is movable within a chamber 40 provided in the end casing I4. The valve passage 28 communicates with this chamber 4.6

through the agency of a longitudinal erway 42 and a port 44 provided in a rotary balancing member 46, later to be described. In this manner fluid pressure in the chamber 46 is equal to the fiuid pressure at the opposite end of the valve member, thereby maintaining said valve member in balance. r

The left extremity of the valve member I2 makes a slotted 'connection with the free end of an arm 48 which is supported by a vertical shaft 50. The upper extremity of this shaft 50 is se- 'cured to an operating levier or handle 52. Thus, it will be .apparent that when lateral' movement is imparted to the` handle 52, the valve member I2 will be movedv longitudinally within its casing, To prevent leakage of fluid'along the vertical shaft 5ML-provide suitable packing 54, and lthe lower extremity of said shaft rests upon a suit--L able threadedf member or plug 56.

Assumeithat the lever 52 is shifted to the right from its neutral position shown in Figures 1 and vfi so as to shift the valve member I2 to the position shown in Figure 6. In this position lthe annular valve passage 28 communicates with a -pipeline 58, which is adapted to be 'connected with one end of any suitable iiuid operated means, such as one end of an actuator cylinder 59 which carries a piston 59a. The central section -I2a of the valve member when in this'position closes communication between the branch passage 24 and the valve passage 34, and thus al1 of the fluid introduced through the pipe line 22 is directed through the valve passage 28 and thence outwardly through the pipe line 58. Fluid from the opposite side of the actuator cylinder 59 is returned through a pipe line 60, which at this particular interval communicates with a peripheral valve port 62. This Avalve port `62 communicates-with a longitudinal valve passageway 64 which opens into the end chamber 32.

At this point attention is directed to,the fact 'that uuid from the chamber sz is directed through the return pipe line 36 through a restricted orifice 65 and then into the reservoir 35. This restricted orifice 65 serves to set up back pressure within the hydraulic system. yIn other words, the gear pump 23 serves to impart rapid traverse movement to the piston 59, as well as to other pistons late; to be discussed, and fluid from the advancing side ofthe piston 59 must be nraint'ained under a predetermined pressure to maintain the proper functioning thereof.. The restricted joriiice 65 causes suillcient back pressure to `be established within the system for this purpose, Even when the valve member I2 occupies its neutral position, this restricted orice 65 serves to maintain the required amount of pressure within the opposite ends of the valve member to maintain the same in balance.

If it is desirable to control the delivery of fluid to another actuator cylinder 61 carrying a piston 61a, a pipe line 58a corresponding to the pipe line`58 is employed which is adapted .to be connected to one side of the actuaton/ A return pipe line a corresponding to the pine'lin 60 communicates with the longitudinal valve passageway 64 through a peripheral valve port 62a when the valve member-I2 occupies the position shown in Figure 6., It will tbe apparent from the foregoing that when the valve member I2 occupies the position shown in Figure 6, fluid may be directed to a plurality of actuators such as cylinders 59, 61, and 69.

I have disclosed in the circuit diagram of Figure 8 a plunger pump 1I which is connected may be driven from any suitable source of power supply. In my above mentioned co-pending application I have disclosed the same coupled di-"t rectly with the spindle of a lathe, and in Figure 8 I have shown this spindle diagrammatically and designated the same by the numeral 16. To

control the coupling and uncoupling of the plunger pumps 1I and 13 with their source of power supply, I employ a hydraulic actuator 1li, Y

Figure 8, which includes a piston 11a, reciprocably mounted within a cylinder 11b. This piston 11a may be coupled with a clutch mechanism (not shown),A and it will be apparent from the description about to follow that, when the valve member I2 is shifted to the left or the right, vthis actuator piston 11a is automatically shifted so as to control the coupling of the high pressure plunger pumps 1I and 13 with'respect to their source of power supply. For a clearunderstanding of the present invention it is not necessary to specifically disclose the clutch mechanism,y nor is it essential to disclose the structural features of the mechanism for drivingfthe spindle 15.

For a more detailed explanation of these driv-` serve to move the clutch actuating piston 11d to the left, thereby causing connection to be established between the spindle 15 and its source of power supply, such as an electric motor 19 shown diagrammatically in Figure 8. The 4left position of the valve member I2 may be referred to as the rapid approach position because in this position the actuator pistons 59a and 61a experience a rapid forward movement in response to uid directed thereto through their companion pipe lines 58 and 58a. When the valve member is again shifted from its rapid approach position to its neutral position, the gear pump 23 is rendered functionally inoperative for propelling purposes with respect to the actuator pistons, and the plunger pumps 1I and 13 function independently for supplying fluid under relatively high pressure to the rear end of the cylinder 59 and the right end of the cylinder 69. In other words, theA pistons 59a and 69a are moved at a feeding rate in response to the actuation of the plunger pumps independently of the actuation of the gear pump 23.

Assume that the valve member I2 is shifted to its extreme right or reversing position s hown in Figure 7. In this vposition the valve member I2 causes all of the fluid from the branch passages 24 and 26 to be delivered to the annular valve passage 34.l This valve passage 34 now communicates with the pipe lines 60 and 60a, and thereby causes fluid to be displaced in a reverse direction through said pipe lines to impart reverse rapid movement to the actuator pistons 59a. and 69a. The pipe lines 58 and 58a now serve as return lines and communicate with the peripheral valve the returnpipe line 36 and the restricted orice 65 to the iluid reservoir. l

,Thus far I have described the manual operation of the valve mechanism, and I shall now proceed to describe the automatic control thereof. Referring to Figure l, it will be seen that I have shown a fragmentary portion of a slide 66 which is horizontally Kshiftable within ways provided within the machine frame 26. Movement is im# parted to this slide 66 by means of a gear 68 l0 which meshes with a rack 10 extending along the underside of the slidef This gear is mounted upon a shaft 12 and rotation is imparted to said shaft inresponse to movements experienced by other machine elements, as, for example, ythe l5 movementof a tool supporting carriage 8| shown fragmentariiy in Figure 9. This arrangement isY shown more in detail in my aforementioned copending application. The slide 66 is equipped with a plurality of adjustable dogs 14, 16, and 18. 20

The dogs 14 and 18 are designed to engage a depending lug 8|), which is carried at the outer extremityof a rod 82. The lug may be swung upwardly out of the path of movement of the dogs 14 and 16 by merely pulling outwardly on 25 the part from which the dogs extend, 'and then giving said part a slight rotary movement.

The rod 82 is mounted withinasleeve 84 which is formed integral with the end casing I6. An

arm B6 extending laterally of the control lever 30,

52 makes a slotted engagement with one end of the rod 82, and thus when the handle 52 is swung to the right soas to carry the valvev member I2 to its forward position shown in Figure 6, the depending lug 80 will be moved forwardly to a posi. tion which lies in the path of movement of the dog 14. Thus, at a predetermined interval the dog 14 will be carried into engagement with the lug 83 so as to return the valve I2 to its neutral -40 position.

Shifting the valve member I2 to its neutral position instantly renders the low pressure circuit functionally inoperative with respect to the propulsion of -the actuator pistons, and the plunger pumps 1I and 13, which are coupled with 45 their source of power through the operation of the hydraulic clutch actuator 11, serve to move the actuator pistons at a feeding rate. In other words, in its neutral position, the valve member I2 renders the high pressure circuits, which in- 50 clude the plunger pumps, functionally operative, and the lo'w pressure circuit, which includes the gear pump 23, functionally inoperative. The 'fluid dispatched from the gear pump 23 circulates through the valve at very low pressure, inasmuch as the only pressure to be overcome is that which results from the presence of the restricted orifice 65.

.The continued forward movement of the slide 66 will eventually carry the dog 16 into engage'- ment with a bell crank arm 88. The other arm 99 of this bell crank has a slotted connection with a rack bar 92. This rack bar 92 is constantly urged outwardly through the action of a coil spring 94, Figure 5, and meshes with teeth provided along a peripheral portion of the balancing member 46. When the dog 16 engages the bell crankarm 88, the rack bar 92 is urged to the left, Figure 5, thereby imparting a rotary movement to the balancing member 46. This movement seversjv'm from within the chamber 49 to pass freely through 7 the pipe`1ine 96, thereby unbalancing the valve member so as to effect the immediate shifting thereof to the positionshown in Figure '7. lIn other words, by shifting the balancing member 46, fluid pressure -is relieved and the normal fluid pressure at the opposite end of said valve causes the immediate and suddenv shifting thereof to the right. This causes a reversal of fluid in the circuits with which the valve mechanismV is connected, and as soon as the dog 16 is moved away from the bell crank arm 88, the spring 94, Figure 5, causes the automatimshifting of the balancing member 46 to its normal position. A pin 9,8, Figures 1 and 5, extends within a transverse slot |00 and serves as an abutment to eiect the registration of the port 44 with the longitudinal passage 42. As soon as this passage and port are moved into registration, the balanced condition of the valve member is again established. V

In this connection it is to be understood that the valve member I2 may be shifted to its reverse position by means other than the above men- ;tioned balancing mechanism. f In other words.

dogs or other` mechanical devicescarried by the slide or other parts of the machine may be em- .ployed to automatically shift the valve member without departing from the spirit and scope of the invention. In fact, the balancing mechanism merely represents one arrangement .whereby the reversing ofthe valve member may be accomplished. It will also be understood that when the slide 86 has been reversed through a sufficient distance, the dog 18 will be carried into engagement with the depending lug 80 so as to cause the valve member l2 to be automaticallyA shifted to its neutral position.

I employ a pair of bleed passages |02 and |04, Figure 2. which communicate at their inner extremities with the end chamber 32 ,when the valve member occupies its neutral position,

,These bleed passages are employed as a precaution against the possibility of leakage inthe actuators or` pistonswith which the valve mechanism is coupled. In other words, it is only necessaryr to use these bleed passages in instances where compensation must be' made for iiuid leakage resulting from wear'in the actuator cylinders 59, 61, and 69. They merely serve as compensating means to prevent the building up of too great a pressure on the advancing side of said pistons. Thus, if excessive pressure should be built up within 'the actuator cylinders, the bleed passages i02 and IM serve as restricted openings through which iiuid may pass to relieve 'against the development of such pressure.

Referring particularly to Figure 1, it will be noted that when the valvemember I2 is initially shifted to the left, communication between the branch passage 24 and the chamber 32 becomes restricted. 'Prior to this restriction the normal flow of iuid from the conduit 22 takes place through the branch passage 24 and thence into the chamber 32 because less frictional resistance due to bendsis occasioned along that path than is occasioned in the path which includes the branch passage 28, the passage 28, the annular 'groove 4I and the passage 30. However, as the valve section moves to.the left so as to partially cut of! the branch passage 24 fromthe ,chamber 22, a.

sudden building up of pressure within the branch l'lassases 24 .andi-2B and consequently within the passage 28 takes'place. 'This causes an increase in' id pissure toitake place within the passag I a` "the passage 42, hence an increase in within the chamber 40 which communicates with the passage 42. This increase in Ypressure is sufiicient to insure the sudden and continued movement of the valve member I2 to the leftafter it has been initiallyshifted through the action of the dog on the slide 63. It will be apparent from the drawings that the size of the annular passage 4I in comparison with the cross sectional area of the passages 30 and 42 is such as to prevent restriction between the passage 28 and the passages 30 and 42 until the valve section 38 has shifted a considerable distance to the left. In other words, no restriction between the passage 28 and the passage 42 takes place which might introduce a throttling action within said passage, as the section 38 moves to the left. Bearing in mind that the valve member l2 is maintained hydraulically in balance as a result of the substantially equal pressures within the chambers 32 and 40, it will be readily appreciated that only a relatively slight building up of pressure within the chamber 40 is necessary to cause the shifting of the valve member to the left as described above. Thus, when the valve member is shifted to the left from the position shown in Figure 1, the communication between the passage 24 and the chamber 32 is restricted, thereby causing a uniform increase in pressure which is transmitted to the chamber 40 in the manner vjust described. y

From the'foregoing it will be apparent that my invention contemplates the provision of a, simple, durable, and eii'ciently,l operable valve mechanism. It will be noted that the central casing or sleeve in which the valve member is shiftable is relatively short, and may be very accurately machined and ground so as to positively prevent the possibility of any leakage along the surface of the valve member. This i's to be clearly distinguished from other types of shiftable cylindrical valves which have been used heretofore in connection with hydraulic actuator systems, wherein a relatively long unitary valve member has been employed in order to control the displacement of both high and low pressure fluids, and in order to render the valve capable of at least ve different positions.u In my construction the valve has only three positions, namely, a neutral position, a forward position, and a reverse position. Hence, the valve is only subjected to a relatively short movement. The convenient arrangement of the valve ports and passages is such as to make for the utmost simplicity in design and efliclency in operation. Myimproved valve mechanism serves as an effective means for controlling the delivery of low pressure fluid to a plurality of actuators with a minimum amountof effort and skill on the part of an operator. Conventional types of uid controlled valves as aforementioned are employed to govern bothlow and high pressure fluids, and consequently any selection of said fluids must be made through said valve. When such a valve is placed in neutral position, no movement of the tuator takes place without moving said valve. Q y improved valve mechanism is such that when the valve is placed in neutral pbsition, it may be readily operated through the action of an actuator which is controlled by a separate circuit.

In otherwwords, my valve may be used inA a low pressure circuit which is entirely independent of through the action of the feeding or high presair. within the actuator cylinder 59 at the advancing sure circuit. For a clear disclosure of one practical application of this arrangement, I wish to again make reference to my above. mentioned co-pending application.

It will also be noted that the bleed passages |02 and |04 serve to take care of slight leakages which occur in the actuator cylinders. For example, consider-thc functioning of the bleed passage |04 which maintains restricted communication be- Vtween the conduit 60 connected with the `actuator cylinder 59 and the valve chamber 32 which is constantly subjected to a predetermined fluid pressure as a result of the presence of the restrictedoricel mechanism 05. Thustheareawithin the actuator cylinder 59 presented at the advancing side of the piston 59a during the feeding stroke thereof is constantly maintained at a pressure which is at least as great as the pressure present in the valve chamber 32. This serves then to account for any slight fluid leakage which may take place in/ the actuator, and also maintains suiiicient pressure inl the actuator cylinder to positively preclude the presence of In other words, if the pressure of the fluid or discharge side of the piston 59a drops to zero and any leakage occurs, the tendency wouldbe for air pockets to form and thus introduce serious pulsating effects. However, the presence of the bleed passage |04 serves to maintain the fluid at a pressure suilcient to exclude any air. It will also be noted that the bleed passages |02 and |04 will serve to take care of any volumetric differences which result from the presence of a piston rod onI only one side of the actuator pistons. Thus, as the actuator piston 59a moves forwardly, a greater volume of fluid will be discharged than that which is taken in at the opposite side of the piston. This excess uid'can passoutwardly through the bleed passage |04. At this point it` must be understood, however, that thebleed passages |02 and |04`are so small as to in no way impair the functioning of the closed cuit in which the actuators are connected-.with the feed pumps during the feeding strokeg- Attention is also directed to the presence in the casing section I4 of an annular groove 4|, Figures 1 and 2. This annular groove 4| merges with a central grooved area provided by chamfers formed at the connection of the casing section I4 with the central section I0. This annular groove construction erves to continuously maintain communication etween the passageway 30 and the passageway 42.

vco

. movement.

Attention is directed to the fact that my improved valve mechanism has a very practical 'application in connection with actuating members or pistons which are vertically reciprocable. In common practice both ends of such apiston remain in communication with the fluid circuit when the main control valve is' in its neutral position. In other words, the main control valve does not serve to disconnect the actuating piston from the pump. What the valve really does is Ato permit the fluid to be by-passed, and hence` prevents the/'application of fluid pressure against the piston. Hence, when the piston is 1 subjecting the actuator piston to any fluid pressure.

Thus, when my improved valve mechanism is employed, the actuating mechanism such as a cylinder and the actuator piston may be placed in any plane and subjected to any load without' imparting movement thereto when the valve is in its neutral position. In other words, by moving my valve to its neutral position, the actuating mechanism or piston with which it is connected is cut oiffrom the pump as distinguished.

from the conventional valve which, when moved to neutral position, causes both ends of the actuator piston to be subjected to the by-passing pressure. From the foregoing it will be apparent that my valve mechanism has a very practical application.

In conventional types of valves for controlling iiuid circuits, whichmust be shifted past a neutral point, auxiliary means are usually provided for shifting such valves past said neutral point. In the valve of the present invention I employ no auxiliary force to shift it past its neutral point. In fact, it is only necessary to relieve the fluid at one end of the valve casing, thereby permitting the normal pressure of the uid at the other extremity to act upon the valve. Ordinarily, in machine construction having one mechanism for propelling an actuator or machine part at a given rate and another actuator for propelling said f the other circuit rendered functionally operative without introducing the slightest degree of pulsation in the circuit and without the necessity of employing auxiliary devices for effecting the shifting of thev valve.` 'I'hat is tosay, my valve construction is particularly adaptable in circuits of the type shown in Figure 8, wherein fluid at relatively low pressure is employed for rapid traverse .purposes and high pressure fluid for feeding purposes., My valve so controls the functioning `of the low and' high pressure circuits as to render the operation of one absolutely independentof the operation of the other. By employing my improved valve construction, I am able to maln- `tain two propelling mediums, namely, the high pressure and the low pressure fluids, functioning so that instantly upon the cutting out or clipping off of one fluid, the other is rendered functionally operative without introducing any interruption or non-uniformity in action of the hydraulic actuator as the result of switching from one fluid to the other.

In fact, by employing thev particular type of valve shown in the drawings,

I have been able to effect a reversal of a hydraulically propelled machine tool within the limits of two-tenths to four-tenths of a thousandth of an inch. In other words, I am able to control the point at which the reversal takes place during'- each cycle of operation of the machine tool within the above mentioned limits. In fact, valves of the type disclosed in this application have been subjected to the severest tests under actual operating conditions, and these tests have proven very satisfactory. In using material working apparatus, such as lathes, milling machines, and the like, for production work, said machines are 'set up so as to repeat cycles of operation, and thereby enable similar work pieces to be acted upon in rapid succession. In such instances the machine must be set up 'so that the machine tool will shift from feed to rapid traverse movement at a point which must necessarily be'determined oy the nature or structure of the work piece for which the machine is set up. My improved valve constructions enables a hydraulic actuator for propelling a machine tool to be shifted from feed to rapid traverse movement at the proper instant and without the slightest degree of iiuid pulsation.

Having thus described my invention what- I claim as new and desire to obtain by Letters Patf determined shifted position, a passageway for temporary unbalanced fluid pressure to insure the receiving iluid from an external source of Asupply, said valve ports being contemporaneously and selectively connectible for fluidconducting purposes with said passageway, means for conducting fluidreturned throughone of said ducts away from said valve mechanism, and a second passage communicating with said last mentioned iluid conducting means and arranged during the shifting of the valve member in a given directionto establish temporary restricted communication with one of said valve ports, whereby to effect a complete shifting of the valve memberv in said given direction. l v

2.' In a-valve mechanism for'use in hydraulic actuator systems, a valve casing, a valve member normally maintained in balance by fluid shiftable within said casing, a pair of spaced valve ports in said member, a duct for communicating with one of said valve ports when said valve occupies a predetermined shifted position, a second duct for communicating with the other valve port when said valve port occupies another predetermined shifted position, a-passageway for receiving fluid from an external source of supply, said valve ports being contemporaneously and selectively connectible for fluid conducting purposes with said passageway, and means including a peripheral port and a communicating longitudinal passageway in the valve member open at one end of said member and closed at the other end thereof for receiving fiuid'returnedthrough one of said municating with,A one of said ports, a fourth duct communicating with the other port, means. for conducting fluid returned through one of said ducts away from`Y said valve mechanism, and means `for causing a sudden temporary increase in fluid pressure within the valve during the shifting 'thereof to insure the sudden and complete movement of the valve member in a given direc' tion.

4. In a valve mechanism for use in hydraulic actuator systems, a valvev casing, a valve member normally maintained in balanceby fluid shiftable within said casing, a pair of spaced valve ports in said member, an intake passageway comprising a pair of branch passages adapted for common connection with an external source of fluid supply, one of said branch passages being positioned for communication with one of said valve ports and the other branch passage being positioned for communication with the other valve port,` aduct for providingexternal communication with one of said valve ports, another duct for establishing external communication with the other valve port, said valve ports being adapted for contemporaneous and selective communication with said branch passageways, for fluid conducting-purposes, and means opening at one' actuator systems, a valve casing, a valve member shiftable within said casing, Va passageway having two spaced terminals opening into said casing, -a duct for connecting said passageway with an external source of fluid supply, a pair of spaced ports in said valve member adapted to selectively communicate with the terminating portions of said passageway, a duct connectible with one of said ports, a second duct connectible with the other port, a second passageway for connecting one of said ports with one extremity of the valve member and arranged for temporary restricted communication with said last mentioned port during the shifting of the valve member in a given direction to cause' a temporary and sudden increase of fluid pressure within said port,"where by to insure the sudden and complete movement oi? the valve member in said given direction, and

means for conducting fluid from one of -said ducts to a point externally ofI the valve mechanism. v

6. In a valve mechanism for use in hydraulic actuator systems, a valve casing, a valve member normally maintained in balance by fluid longitudinally shiftable within said casing, said' valve member being provided with acentral cylindrical section which is slidable within the cas, ing, a valve port positioned at each extremity of said central section, a passageway for receiving fluid from a point externally of the valve casing, said passageway having spaced terminating portions opening into said casing and adapted to be opened and closed by said central valve section,

a duct connectible with one of said ports, a second duct connectible with the other port, a second passageway, vsaid second passageway being open to one end of the valve memberl and closed to the other, and a third port in said central section communicating with said second passageway for selectively communicating with said ducts and arranged to conduct fiuid returned through one of said ducts.

7. A valve mechanism for controlling iiuid m a hydraulic actuator system for shifting machine elements which includes a central casing section, a pair of end casing sections, a valve member shiftable within said sections, said valve member and central casing section having cooperative ports for controlling the dispatching of fluid, a control handle oonnected with said valve and supported by one of said end sections for effecting the shifting thereof, and a shiftable actuating member carried by one of said end sections, one extremity of said member having means adapted to be positioned for engagement by a shiftable machine elementand the other extremity thereof operatively connected with said control handle.

8. A valve mechanism for use in hydraulic actuator systems for shifting machine elements including a, valve casing, a valve member longitudinally shiftable within said casing, a pair of spaced valve ports in said member, a passageway providing means for establishing external communication with said casing and adapted to communicate with said spaced valve ports, a duct for establishing external communication with one of said valve ports, another duct for establishing external communication with the other valve port, means for conducting the returned fluid away from said valve mechanism, mechanism for `effecting the unbalancing of the normal fluid pressure within the valve casing without causing an increase in said normal pressure, said mechanism being operable in response to the movement of-the shiftable machine element, a shiftable actuating member supported by the casing, said member being operatively connected with the valve member, and a section carried by and movable with respect to said shiftable valve actuating member, said section being adapted when in one position to be engaged by a shiftable machine element and when in another position to be'cleared by said shiftable machine element.

9. In a valve mechanism for controlling hydraulic actuators and the like, a casing, a valve member relatively shiftable with respect to said casing, said valve member having afluid conducting port, a passageway connectible with an ex-l ternal source of supply and adapted to communicate with said valve port, ducts for directing fluid to a point externally of said valve mechanism, means for contemporaneously blocking both of said ducts when said valve member occupies a given position within the casing, and means for effecting the by-passing of fluid from said passageway when said ducts are blocked by said-valve member and adapted in cooperation with and upon the shifting of said Valve member to present a restricted discharge opening for the `uid in said passageway, whereby to effect a temporary and sudden unbalancing of the fluid presadapted for selective communication with said passageway, ducts for directingv fluid from the passageway to a point externally of' said valve mechanism, said valve ports being selectively connectible with said ducts, means for contemporaneously blocking both of said ducts when said member occupies a given position, and means for eiecting the by-passing of fluid-from said passageway when said ducts are blocked by said valve member including a second passageway arranged ports, 'another duct for for temporary restricted communication with the rst mentioned passageway during the shifting of the valve member, whereby to effect a sudden and temporary unbalancing of the valve member to insure the sudden and complete shifting thereof in a given direction.

11. In a valve mechanism for controlling hydraulic actuators and the'like, a casing, a valve member shiftable within said casing, said valve member having a fluid conducting port, a passageway connectible with an external source of supply and adapted to communicate with said valve port, ducts for directing fluid to a point externally of said valve mechanism, means for contemporancously blocking both of said ducts when said valve member occupies a given position within the casing, and means for effecting the unrestricted by-passing of fluid fromsaid passageway when said ducts are blocked by said valve member and a temporary restricted by-passing of fluid from said passageway following the initial shifting of the valve member in a given direction, whereby to cause a sudden and temporary unbalancing of the valve member to insure the movement thereof.

12. In a valve mechanism forcontrolling hydraulic actuators and the like; a valve casing having a chamber at one end thereoffor receiving balancing lluid, a valve member within said casing having a port, said casing and member beingrelatively shiftable so as to occupy one of at least three positions, namely, a neutral position, an advance position and a reverse position, a

-passageway connectible'with an external source of fluid supply and adapted to communicate with said port, ducts for directing fluid to a point externally of the valve mechanism, means for effecting the contemporaneous blocking of both of said ducts when said valve member and said casing occupy said neutral position, -means for effecting the by-passing of fluid from said passageway when said duets are blocked including a passageway arranged for continuous communication with the chamber at one end of the casing, andvmeans for controlling the hydraulic unbalancing of the fluid within said chamber to cause the hydraulic shifting of said valve member.

13, In av valve mechanism for controlling hydraulic actuators and the like, a casing, a valve member relatively shiftable with respect to said casing,` said valve member having a fluid conducting port, a passageway connectible with an externall source ofv supply and adapted to communicate with said valve port, ducts for directing fluid to a point externally of said valve mechanism means for contemporaneously blocking both of said ducts when said valve member occupies a kgiven positionwithin the casing, means including a passageway extending within the valve casing for conducting fluid at one side of said casing from said passageway to the opposite side of said casing when said ducts are blocked,l and means for controlling the hydraulic unbalancing of the valve member.

14. In a control mechanism for use in hydraulic actuator systems. a valve housing, a valve member shiftable within said housing, a pair of spaced valve ports in said member, a passageway adapted to communicate with said spaced valve ports for conducting fluid thereto from an external source of supply. a duct for establishing external communication with one of said .valve establishing external communication with the other valve port, said the release of the uid from one of said chambers whereby to enable said valve member to be automatically and suddenly shifted in response to, the fluid pressure normally existing within 'Y the other chamber, and means for directing away from said control *mechanism fluid returned through saidports.

15. In a control mechanism for use-in hydraulic actuator systems, a valve housing, a valve member shiftable within said housing, a pair of spaced valve-ports in said member, a passageway adapted to communicate with said spaced valve ports for conducting fluid thereto from an external source of supply, a duct for establishing external communication with one of said valve ports, another duct for establishing external communication with the other valve port, said valve member in one position serving to block both of said ducts, chambers in said housing for receiving fluid from the passageway and disposed so as to normally maintain fluid therein under equal pressures wherebyto hydraulically balance said valve member, means including a shiftable member having a fluid conducting passage for effecting the release of the fluid from one of said chambers whereby to enable said valve member to be automatically and.v suddenly shifted in response to the uid pressure normally existing within the other chamber, and

means for directing away from said control mechi anism fluid returned through said ports'.2=

16. In a control mechanism for use in hydraulic actuator systems, a valve housing, a valve member shiftable within said housing, a pair of spaced valve ports in said member, a passageway adapted to communicate with said spaced valve ports for conducting uid thereto from an external source of supply, a duct for establishing external communication with one of said valve ports, another duct for establishing external communication with the other valve port, said valve member in one position serving to block both of said ducts,` chambers in said housing for receiving fluid from. the passageway, a second passageway forestablishing communication between said chambers and disposed so as to normally maintain huid therein under equal pressures whereby` to hydraulically balance said valve umember, means for effecting the release of the fluid from one of said chambers whereby to enable said valve f member to be automatically and suddenly shifted in response to the fluid pressure normally existing within the other chamber, and means for vdirecting away from said control mechanism fluid vreturned through said ports.

17. In a control mechanism for use in hydraulic actuator systems, a valve housing, a valve member shiftable within said housing, a pair of spaced valve ports in said member, a passageway adapted to communicate with said spaced valve ports for conducting fluid thereto from an external 'vurce of supply, a duct for establishing external communication with one of said valve ports, another duct for establishing external communication with the other valve port, said valve member the passageway andl disposed so vas to 'normally maintain fluid therein underequal pressures whereby to hydraulically balance said valve memy Y, are blocked, means for effecting the release of the fluid from one of said chambers whereby to enable said valve member to be automatically and suddenly shifted in response to the fluid pressure normally existing within the other chamber, and means for directing away from said control mechanism fluid returned through said ports..

18. In a control mechanism for use in hydraulic actuator systems, a valve housing, a valve member shiftable within said housing, a'pair of spaced valve ports in said member, a passageway adapted to communicate with said spaced valve ports for conducting fluid thereto from an external source of supply, a duct for establishing external communication with one `of said valve ports, another duct for establishing external communication with the other valve port, said valve member in one position serving to block both of said ducts, chambers in said housing for receiving fluid from the passageway and disposed so as to normally maintain fluid therein under equal pressures whereby to hydraulically balance said valve member, means for effecting the release of the fluid from one of said chambers whereby to enable said valve member to be automatically and suddenly shifted in response to the fluid pressure normally existing within the other chamber, and means including a restricted discharge orifice for receiving fluid from the valve housing whereby to maintain the required pressure conditions within said housing.

19. In a control mechanism for use in hydraulic actuator systems, a valve housing, a valve member shiftable within said housing, said member being adapted to occupy three shifted positions, namely, a neutral position, a forward position, and'a. reverse position, a pair of spaced valve ports in said member,a passageway adaptedA to communicate with said spaced valveports for conducting fluid thereto from an external source of supply, a duct for establishing external communication with one of said valve ports, another duct for establishing external communication with the other Valve port, said valve member in its neutral position serving to block both of said ducts, and in yone shifted position to establish communication between one of said ports and one of' said ducts, while in the other shifted position t establish communication between the other port and duct, chambers in said housing for receiving fluid from the passageway and disposed so as to normally maintain fluid therein under equal pressures whereby to hydraulically means to control the shifting of the valve member to its forward position, and means for effecting the release ofthe fluid from one of said chambers whereby to enable said valve member to be automatically and suddenly shifted to its reverse position in response to the fluid pressure normallyrexistin'g within the other'chamber, and means for directing away from saidvalve housing fluid returned through said ports.

20. In a control mechanism for use' in hydraulic actuator systems, a .Valve housing, a valve member shiftable within saidhousing, a pair of spaced valve ports in said member, a passageway adapted to communicate with said spaced valve ports for conducting fluid thereto from an extemal source of supply, a duct for establishing external communication with one of said valve y balance said valve member, manually operable 5 for receiving fluid from the passageway and disposed so as .to normally maintain iiuid therein under equal pressures whereby to hydraulically balance said valve member, means for eiectin'g the release of the iiuid from one of said chambers 10 whereby to enable said valve member to be automatically and suddenly shifted in a given direction in response to the iiuid pressure normally existing within the other chamber, said valve member during the movement thereof in the opposite direction cooperating with said passageway to temporarily restrict the discharge of fluid from said passageway, whereby to cause a temporary, sudden increase in pressure actingA to insure the complete shifting of the valve member in said opposite direction, and means for directing away.

0 external communication with one of said valve ports, another duct for establishing external communication with 'the other valve port, said valve member in one position serving to block both of said ducts, means for directing away from said control mechanism iiuid returned through said ports, and a bleed passagefor` establishing restricted'communication between one of said ducts and the iiuid delivered through said passageway when the valve member blocks said 4o ducts.

22. In a control mechanism for use in hydraulic actuator systems, a valve housing, a'valve member shiftable within said housing, a pairv of spaced valve ports in said member, a passageway 45 adapted to communicate with said spaced val`ve p orts for conducting vfluid thereto from` an external source of supply, a ductfor establishing ex- 'ternal communication withbne of-said valve ports, another duct for establishing external 50 communication with the other valve port. said valve member in one position serving to block Vboth of ducts, means for maintaining said valve member hydraulically in balance, means for directing awa'.r from said control mechanism fluid returned .through said ports, and a bleed` passage for establishing restricted communication between one of said ducts and the iiuid delivered'through said passageway when the valve member blocks said ducts.

23. In a valve mechanism for use in hydraulic actuator systems, a valve casing, a valv'e member normally maintained in balance by fluid shiftable within said casing, a pair of spaced valve ports in said member, a duct for communicating vwith one of s aid valve ports when said valve occupies a predetermined shifted position, a second duct for communicating with the other valve port when said valve port occupies another predeter- K mined shifted position, a passageway for receiving fluid from an external source of supply, said valve ports being selectively connectible for iiuid conducting purposes with said passageway, and means including a peripheral port and a communicating longitudinal passageway in the valve member open at one end of said member and closed at the other end thereof for receiving fluid returned through one of said ducts.

24. In a valve mechanism for controlling hydraulic actuators and the like, a valve casing having a chamber at one end thereof for receiving balancing iiuid,l a` valve member within` said casing having a portion exposed to the pressure within said chamber having a port, said casing and member being relatively shiftable so as to occupy one of at least three positions, namely, a neutral position, an advance position and a reverse position, a passageway connectible with an external source of iluid supply and adapted to communicate with said port, ducts for directing uid to a point externally of the valve mechanism, means for effecting the contemporaneous blocking of both of said ducts when said valve member and said casing occupy said neutral position, means for eiecting the by-passing of iluid from said passageway when said ducts are blocked including a passageway arranged for continuous communication with the chamber at one end of the casing, and means for causing the hydraulic unbalancing of the fluid within said chamber to cause the hydraulic shifting of said valve member.

ERNEST J. SVENSON. 

